


Back to Mach

by ramblingfangirl



Series: Those he forgot [3]
Category: The Transformers (IDW Generation One), Transformers - All Media Types
Genre: Angst and Romance, Cybertronian Civil War, Eventual violence, Investigations, M/M, Mnemosurgery, Police, people make bad decisions
Language: English
Status: In-Progress
Published: 2018-06-11
Updated: 2018-08-05
Packaged: 2019-05-21 00:45:15
Rating: Teen And Up Audiences
Warnings: Graphic Depictions Of Violence
Chapters: 2
Words: 4,827
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/14905292
Author URL: https://archiveofourown.org/users/ramblingfangirl/pseuds/ramblingfangirl
Summary: For a while, despite the war, Mach could honestly have said he wasn’t doing too badly.He had a conjunx who he loved dearly and a job which he also loved dearly, carrying out investigations with his partner-in-law Tackle.But then one investigation comes along that’s more personal than any he’s ever taken before.And as he goes down that road, he’s forced to question whether certain things and the lengths you go for them are even truly worth it at all.





	1. Prologue: "Hello, hello"

**Author's Note:**

> Decided to try write something for Mach too, taking some cues from his Victory depiction to help decide how to characterise him.  
> The prologue was originally quite a bit longer, but I decided to split it down to use different parts in different places.
> 
> I hope you enjoy reading!

He always loved it when he got to fly.

The peace and quiet of it all, which made it so much easier to think, up in the sky with just the wind around you, watching all the sights that Cybertron had to offer below as well as its wonderful stars shining above.

So, it was a good thing that doing so was part of his vocation.

An advantage of getting himself declared alt-mode exempt. Despite only being a _shuttle_ , he got to experience the tremendous honour of working in the forces as an officer!

Even if often he _was_ still mostly utilised as essentially a delivery shuttle, taking packages from one district to the next.

 _This_ particular package here was one that had to go to Officers Prowl and Tumbler.

Tackle had been very insistent on stressing the importance of this one. Going into all sorts of specifics on forensic details and minute which Mach didn’t _entirely…get_.

But Mach knew the case. Had read up all the details about it over and over and over as each new intriguing one came in. Getting all the science of it or not, he was more than happy to help however he could in solving crime!

And even just looking at the package it could immediately be told just how important it was.

That being why it was an especially good thing that it appeared he’d made it to the delivery point, even if it did mean an end to his flight.

He wasn’t going to be late!

He swooped down then, feeling the wind rush around him as he was heading towards the ground, until he was close enough to where he wanted to be that he could smoothly transform and land without any risks.

“Hello-“

“You’re 0.3 minutes late.” Was said before he himself even got the chance to speak another word or take a step forwards himself.

_Was he?_

“I am sorry. I came as fast as I could-” He apologised, moving to-

“Stay back! You’ll disrupt the scene.”

“Officer Prowl, I have been around crime scenes before.” He explained, once again apologetically. “I know what I am doing.”

 “Prowl, we’ve _talked_ about this.” Officer Tumbler, spoke up then, taking Mach’s side in this. “ _We_ requested the delivery. You can’t be rude when the person with it arrives.”

There was a debate then between the two, and, although he listened in and was in fact a significant portion of the topic, Mach wound up staying silent after a few awkward failed attempts to interject.

“Sorry, don’t take this personally.” Tumbler interrupted Mach taking this all personally, at the same time also turning away from and cutting off Prowl.

The two partners exchanged some sort of a look then about that development, but Mach couldn’t tell exactly _what_ that look was.

Whatever it was, it was Prowl who broke it first, turning away and heading off to continue examining the scene.

Although not without getting in one last comment first, about the importance of regulations and punctuality.

“Sorry, I did not mean to cause an argument.” Mach apologised. He really hadn’t, _especially_ not a public one. He would’ve _hated_ it, if someone put him in the same situation as this and very much thought that these two partners here _must_ hate it too.

It was then that Tumbler looked away from Prowl.

“You didn’t. Prowl’s just…You get used to him.” There was a mix of fondness and an immense level of exasperation in the tone there.

“I am sure you do.” Mach nodded along, appreciating how much nicer this officer was being about his tardiness.

 “It’s Mach isn’t it? They said they were sending you.”

“Yes, I am Mach.” He confirmed as he went to peer into his cockpit.

“As for what they sent me with…”

There it was. Taking great care to remove it carefully now, gently, ever so gently, taking off the bindings that had secured it into position throughout his flight.

He then presented it forwards.

_“Well-“_

 

* * *

 

 Well.

It had happened.

He shouldn’t have been surprised.

There had been evidence piece after evidence piece that it was going to go this way, so much so that one needn’t be a detective at all to solve that mystery.

That a war was coming.

The only conclusion that Mach could come to one why he was surprised, was wilful, optimistic blindness that surely something so terrible couldn’t be true?

He didn’t think he liked what that said about him. What sort of detective was one that refused to _detect?_

And now here it is, everything’s gone so _horribly_ wrong and _so many_ are dead that with the sole exception of Tackle, Mach has to be _very_ lucky to see someone alive that he recognised from before.

Which is what he _thinks_ might just be happening now.

He didn’t have long, he was in the middle of an investigation and had a lead to follow, but although the frame looked slightly different he was _sure_ that was him skulking over there.

Bad at reading them as he was, Mach never forgot a face…

…Yes. Yes, it was him! This _was_ someone he recognised!

Officer Tumbler! Mach remembered him, he was nice!

He never knew him _well_ , but he could still take a klik to say hello.

He was confident it would take much longer than that for the trail to go cold, with how _sloppy_ the culprit in this case had been.

“Hello? Hello!” He called out, moving towards the huddled over mech.

“Of-“ Mach cut himself off. Tumbler had left the forces, hadn’t he? He remembered hearing about that, although wasn’t sure what he’d gone too after leaving.

He and _many_ others, there being not much actual official officers left by now. It was all wartime military now and he didn’t think Tumbler had seemed the sort to be a military officer.

But, if he was wrong in making that assumption he’d take the correction and apologise.

 “Tumbler, how have you been? Good to see you are an autobot!” He went on after that thought process, still thrilled to see a familiar person and one wearing the same badge as him too!

The helm of which raised sluggishly, as if fighting against some great, invisible weight.

“It’s…” Visor dimmed and he leaned forward, focusing intently in on him without it. “ _Mach_ , isn’t it? From the forces. It’s been…a while. Good to see you’re autobot too.”

Familiar, if now halting words came out. He didn’t seem quite sure about what he was saying. And the question of how he’d been went distinctively unanswered.

Something that Mach had never once seen be a _good_ thing.

“Yes. Yes that is me. Are you alright?” He tried one more time, happiness at seeing someone being crept in on by a cold, growing, concern.

“I’m fine.”  Was snapped.

Mach always found it odd, how a person could say one thing but their tone clearly mean something else entirely.

In any case, it seemed that the creeping concern was more than justified in being there.

“Sorry.” Tumbler’s apology came relatively quick though. Almost the fastest thing he’d said this entire encounter.  “Brainstorm _keeps asking that_ and- and I’m fine. Just a processor ache it’ll pass.”

That _would_ explain it, but Mach still couldn’t shake an uneasy feeling.

“No worries, apology accepted.” He hurried.

“Is this Brainstorm a friend of yours?” Was then questioned. “If you are in pain, I could try take you to him?”

Hopefully he was nearby.

“He _is_ my friend but-“ The rest of the mumbling reply was too distorted to make it out.

However, one thing could be told: it certainly wasn’t a _yes_.

“Do you want me to _comm_ him?” Mach really felt he should do something. He needed to get back on solving his case, people were counting on him for that, but at the same time it didn’t feel _right_ to just leave Tumbler there. In pain, with a war going on all around him.

_What if something happened?_

Maybe he should call Tackle instead.

Ask him to take over the investigation while he tried to handle this?

He requested a moment from Tumbler- who had once again declined the offer for him reaching out to this Brainstorm- and scuffled off out of the alleyway to make the call in private.

Just in case Tackle was rude, he didn’t want it being overheard.

And rude he _was_. Making it quite plain how unhappy he was about the situation and his thoughts on what Mach was planning on doing.

He couldn’t fault Tackle much though. He just had to apologise and explain that in doing this he was still fulfilling the role he’d gotten the rare luxury in choosing: to protect and serve the public.

That and he had every faith in Tackle to be able to pick up where he’d left off.

He’d join him once again as soon as he could.

He was able to get a reluctant agreement from him with that reasoning.

Now, as for Tumbler…

“Hope you do not mind me sitting down here.” He came striding towards him, surveying the yellow mech to make sure nothing had somehow gotten worse since he’d been gone for it.

As it was, it didn’t seem that he’d moved from his position at all.

Mach wondered if he’d even fully noticed that he’d left.

“I have some case files I need to read through and this seems to be an opportunity to do just that.” Not a lie. Not a lie at all. It was the truth, he did have case files that needed to be read through.

Only thing was, he hadn’t originally intended to do so _now_.

He took a cautious, slow seat down next to Tumbler to see if he was going to say anything in response to that.

“Go ahead.”

The relief he felt was tangible at that.

Even if that was just about the only thing that was said to him at all for most of the time he went on to spend there.

During which, Mach kept glancing up from the files on his data pad, wondering if _he_ should give another go at trying start a conversation.

He was curious about what was going on and worried about the effect it was having, but if he broached it more not the most likely outcome was spooking him off.

Just like with witnesses or suspects. Push them too hard too fast and they’ll just shut down on you. You have to work your way up to these things.

He would just keep Tumbler company for now.

…Until Tumbler spoke up at last, thwarting Mach’s attempts to build up a plan.

“I hadn’t noticed the time. I should go before Brainstorm starts looking.” He’d clearly noticed his internal clock at last, but his attempt to move off was hindered by how he very much still acting like someone severely overcharged on engex.

“I’m not sure you should go.” Mach had to speak up, hurriedly putting away his files.

“I _need_ to go. I can’t- I can’t be found here…”

“Well certainly not _alone_ then! Please, allow me to escort you.” Mach did what was essentially pleading, forcing his voice to take on a more assertive tone in doing so. “It would be no bother.”

“If you insist Officer.” Tumbler said blearily, his concession was accompanied by a scratch at the back of his neck.

_It would be no bother._

Was that statement true?

That _was_ a question.

Mach quickly found that helping him was not _easy_. The _significant_ size difference between the two only making attempts to support even more complicated then they already would have been without it.

Even trying to get his attention could be a task in and of itself, as Tumbler kept on stumbling. Forgetting which direction to turn, as if trying to find some location he’d only ever heard of and not his own home.

So, it was _difficult._

But he wasn’t _bothered_ by doing it.

If anything, that moment when they finally crossed the entrance to Tumbler’s abode, felt rather rewarding.

Mach looked around the accommodation when they did, looking for tell-tale signs as to what might have caused this incident that he’d happened upon.

Circuit boosters. Cubes of engex. Signs of disrepair that often betrayed a frequently excessive user of either of those substances.

That sort of thing. 

Or a theft perhaps? A significant assault could explain the behaviour too. In which case…but no. There were no signs of a fight or a break-in here.

Just as there were no signs of circuit boosters, engex, or even much of a mess.

If anything, the place seemed relatively neat.

And he voiced that. He had just entered the mech’s home after all, it would only be polite to try offer a compliment.

“I…” Tumbler looked over his home then, visor flaring before he replied.

“I never like it here.”

“Hmm?” No attempt was made to quell what could only be described as concerned nosiness there.

“It’s too bare. I don’t know why but it always feels so…” Tumbler trailed off as he lifted his hand up in the air, where it hovered…before he then gave off a sharp wince of pain and it went instead to gripping his helm.

“No offence meant, but as much as talking is enjoyable, I think it would be best if I took you to berth now.” Was innocently spoken.

“I…think I’ll be fine from here. Thank you for your help, I’d rather not have-“

“-Had Brainstorm find out.” Mach filled in, squirming a little there.

That much had been _abundantly_ clear.

But, he wished it had not been brought up again.

He didn’t feel comfortable with subterfuge or secrets.

Not even ones kept from mechs he’d never heard of before.

And especially not ones where keeping them felt harmful, as if the one asking for silence would surely suffer for it if you held your word.

It felt wrong. Like tiny little things were crawling underneath his plating.

“Are you still certain that you would be best not to tell him?”

_“Yes.”_

Mach _hmmm’d_ again, before an alternative, viable idea arrived.

“Well if you feel so strongly about this, would you object to the possibility of meeting with me again?”

He would very much like to be able to check up on him, just even see him now and again. See if he was doing alright.

Not excessively. Not intrusively.

Just one officer looking out for a former.

How it should always be.


	2. Case by Case

**Notes for the Chapter:**

> First of all: thank you so, so much for the reviews as well as the kudos! They mean a lot, I hugely appreciate them and they absolutely just make me really smile to see! 
> 
> This next chapter is a significant time skip from the prologue, so some things alluded to might be unclear, but blanks will be filled in later on in the story.
> 
> I hope you enjoy reading!

Mach held up the energon container to optic level, to give it as close a look as was possible when lacking any sort of specialised equipment, before without a further sound simply pouring it out into cups.

Nothing _looked_ to odd about it, at a glance at least.

He’d just have to see if how it tasted, to verify what he’d heard.

“Tumbler, would you mind putting these on the table for me?”  He asked, picking them up and turning around to face him.

“No problem.” Tumbler nodded, before starting to make his way across the hostile terrain that was a kitchen containing moving boxes still not unpacked.

“Thanking you.” The shuttle provided sweetly, as the cups were removed from his grasp, and he turned towards a miniature container stored on the counter.

Tumbler _had_ commented it on being among the very first things he’d unpacked.

He’d joked that perhaps they should have exchanged its contents, instead of innermost energon for their ritus.

But as it was, Mach simply had a profound weakness for novelty straws and had not wanted them to be damaged by being packed away too long.

Cute, colourful and bizarre looking things as they were.

And currently he was just trying to decide which ones to use for the cups he’d passed on.

Prompting Mach to ask Tumbler if he had a preference yet.

“I don’t mind, I trust you. Pick whatever you think’s best.”

Not _yet_ then.

“I will give you this one.” He displayed a green one too him, shaking it lightly, all the while picking up an orange one for himself.

“I accept your gift.”

There were a few other little things that they still had to sort out before they could properly sit down.

But they both went on to get it all done relatively quickly, so that they could still have _some_ time at least to talk before heading off to work.

The final touch being, of _course_ , moving the vase over onto the table.

The vase that contained a cyberflora of immeasurable value to the both of them and inscribed with their little inside joke: _The murder weapon._

“Use any chirolinguistics of late?”

“Not at all and I haven’t been to Harmonex in centuries either.”

“Good to hear, I would hate to have to lose you now.”

 Went their routine, before they moved onto starting to take sips from their energon.

“ _About_ that sort of topic....”  Was then broached by Mach in a much more serious manner.

“How is the case going on your end? We never got to properly discuss it last solar cycle. Did everything go alright with the corpses?”

Both of them had barely even been home the same time, last solar cycle.

Tumbler had to work to very late for the case, after some new bodies were apparently brought in, and Mach had to work from very early to be able to reach a person of interest in time.

“Here’s the thing.” Tumbler leaned forward. “I…I was _prepared_ for it. Interfacing with corpses is nothing new but…” The lean started edging closer towards being a slump.

“You handle it well.” Mach leaned forward himself, trying to provide a distracting positive. “I know without a doubt that your colleagues must all have good things to say of you.”

“If…something _did_ go awry last solar-cycle, they will not think any less of you and I certainly will not either. You can tell me.”

“It’s not that. I’m used to it I can do it, I can read their memories. The problem was there was nothing to read!”

“Nothing?!” Mach jerked. “Were the processors _missing?_ ”

“Oh, they were _there_. They were just _empty_. We can’t even identify who all of them were.”

It was then that the questions became more rapid-fire.

“Were there signs of any other sort of trauma?”

“They might as well have just dropped down offline. Medical reports brought up nothing but sudden spark failure.”

“And it was only a mneosurgeon who could detect the brain tampering. Something which is _new_. Unless I have missed something?”

“Yes, it’s new. Corpses sometimes have missing, corrupted memories if the processor was damaged but even the newest of build are never _blank_. _So,_ is this still the same killer who has progressed or-?”

“Someone else looking to pass of their own murders as just that?”

“It _could_ be the same killer. I saw it back when I was an officer. Kill some mechs at random as practice or to try conceal the actual target they’d have a traceable motive to want dead.”

“We do need to find out what the motive is and whether they fall into the random, factional or personal categorisations. That should make it easier to narrow down suspects.”

“Makes it harder when you don’t know who the victims are.”

“Correct. I and Tackle will try obtain whatever necessary to identify these victims at least, that should be a respectable first step.”

“Would you like me to get the bodies back from the Institute for you?”

 “Wait, _wait._ ” Mach held a hand up, taken aback. “Are the victims still _there?_ “

 “If you need them out then I can get them to let you borrow.” Tumbler wrung his hands together, not quite meeting his other’s optics.

“Should they not be in the morgue by now?”

That’s where he usually went to look if a corpse needed identifying.

Never had Tumbler had to _go get it for him_ before.

 “You _know_ why they aren’t sending it there yet, love.”

Now that he wasn’t reacting in a spur of the moment and had time to think?

 _Of course,_ he did.

“We need to know.”

Corpses turns up with no memories and the New Institute is behaving twitchy about it?

“Has anyone in your Institute _quit_ recently?”

Even without the New Institute’s reaction, the memories being so out of reach that even his beloved Tumbler with his expertise couldn’t get to them, meant that this person _had_ to have some knowledge of a particular field.

“Nobody’s _ever_ quit.”

They’d evidently looked at the corpses and found a very particular sort of scars.

Something which Mach wasn’t entirely satisfied with Tumbler not just outright _saying_ to him earlier

“Do _you_ think it could be someone currently working then, or has information on the how-to leaked?”

The second would be easier to investigate.

See if anyone had gone to the backstreet looking for finger needle mods.

“Leave that to internal investigations.”

_“Tumbler.”_

“I’m _serious_ love, keep to the politie, you’ll find something there I know it. And if we find something you’ll be the first to know, I promise. You don’t have the clearance to go asking questions there. I don’t want to have to get _you_ out of detainment.”

Had Mach a proper face as opposed to a visor and a mask, his displeasure would have been _very_ evident on it at this point.

But he didn’t even _need_ it to be evident in that way.

His lover still saw it.

“We’ll solve this. I know we can. You just need to trust me. _Please_.”

Various cogs turned in an investigator’s helm.

“I do.” He stressed. That was _not_ the issue here.

“But I do not have to _like_ it.”

And then, because he felt the oncoming self-deprecation deep in his very _struts_ -

“Do not start. That is not me saying I do not like _you_ Tumbler. If I did not I would be back in my own apartment, with better aesthetics.”

Mostly a light-hearted tease there but there was a semblance of truth.

Partially his own fault there though if he had to be honest, and not just because of his boxes.

 At the suggestion of both him and Brainstorm tag-teaming to try resolve the issue of the apparent _emptiness_ he’d insisted it had, it was now full of profession related paraphernalia that his conjunx seemed to think was _quality decor_.

Well, at least Mach could honestly say he now knew a lot more about processors than he _ever_ had before. Who _knew_ what a single cyber gnat could do to one?

And it _wa_ s charming, that level of passion suggested there.

He _loved_ whenever he got to see that.

 “Sometimes I still wonder why you do.”

“There are many mysteries to solve on this planet but that is _not_ one of them. Do you want the list again?”

He took his straw out of the now finished energon and pointed it right at him to accentuate.

“I don’t need that.” Tumbler spoke more bashfully.

But Mach had to argue to the contrary.

Besides, he gave a quick glance to the side to check and…

“I could do with moving along and collecting my things regardless. Time is running short this cycle.” He motioned over to the room’s clock, before moving along and motioning for his lover to come with.

But perhaps, instead of looking at him, he should have instead looked out for-

“Watch out for the- !”

His leg collided straight into one of the many boxes strewn about, with a concerning _crunch_ coming from within.

They froze.

_Oh._

_Oh no._

He quickly started trying to pry it open, to see what the damage was.

His yellow conjunx immediately standing up and moving over to help, sliding other boxes out the way so he had more room to start removing things.

“We really should get those unpacked. You live here now. It should feel like home.”

“We should. Too much clutter in here.” He picked up a cylinder from the box, which then proceeded to have the top half _flop off_.

…At least he’d found the source of the crunch.

 “Perhaps when this case is finished.” He tried precariously see if he could balance the top half back on, before getting up to put that aside for now, lest it get stepped on and broken further.

“But…” He looked back over at Tumbler. “It _already_ feels like home. I do not need my belongings. I have you here with me.”

Mach headed towards what he was looking at and Tumbler put an arm around his shoulder as soon as he reached him, as they both then headed together to where Mach had been trying to reach in the first place.

 “…It feels like home here for me too now. With you here.”

The shuttle fondly leaned further into him at that.

“Does that mean you will do the washing up tonight?” He lightly joked.

And with that the conversation turned to household chores, as they started collecting datapads and assorted knick knacks for work.

Until, that is-

 “I never asked you.” Tumbler realised, stopping so abruptly - datapad in hand - that it was like someone had hit a pause button on him. “You asked me about my end of things but I never asked you about yours!”

“If you wish, I will give you my files to read on it later. If you give me those cadavers.”  Was initially quipped back, reasoning there wasn’t any time to go further into it.

…Although…perhaps, he _should_ go into at least a _bit_ further depth.

 _He’d_ been shown that courtesy by his partner, after all and he knew he wouldn’t be able to stand it if such a response had been given to him.

So, more depth it was.

Even if most of the case Tumbler _did_ know about already.

Because the matter of it was-

 “Not a lot new to say on my end. Other than the new identification directive. The lead last solar cycle turned up nothing.” He admitted solemnly.

“It just…remains hard to stay on top of everything. We still have to contend with Decepticon attacks disrupting evidence, knocking out surveillance and leaving some areas far too unsafe to investigate. That and scavengers stealing the dead.”

With resources so dire, you had to move fast to acquire a corpse, before someone made off with it to siphon any energon left and break down its parts.

Difficult to say how common it was, as you can’t exactly tell how many bodies were stolen if they were gone before they were even reported.

And war time meant missing person reports meant all but nothing when people were constantly being conscripted or deployed or reassigned or even, much as anyone hated to admit it, _defecting_.

So, for all they knew, this serial killer could in fact be much more prolific than it currently seemed.

“None of which is alleviating. And now I am being told that our slippery suspect is liable to be a mnemosurgeon. So now I have to worry about my processor being messed with.”

“I would fix that.” Came an impassioned response as suddenly Tumbler was much closer than he’d been kliks ago.

“It shouldn’t happen, if you stick to the politie.” An impassioned response quickly followed on by a very pointed statement. “But if it came to it, I would fix you. You would be fine. You wouldn’t even have to _notice_ something had ever happened at all!”

“I’m _just_ saying! If you _ask_ not to remember...easy solved. Just like we’ll solve this case.” Tumbler added on hastily, picking up on the ill-wording of that last part all by himself there.

Not an offer he’d ever think of taking him up on, that deletion part there.

Can’t solve a case if you don’t remember it.

That and… _easy solved._

If _only._

Not if the attacker killed him first, like it had with the last apparent victims.

Tumbler might be trying to be reassuring, but no amount of mnemosurgery could bring back a corpse.

“All the same, even if you could get inside me and fix the problem, I will still have to watch my neck more closely now.” But the promise was sweet, so the shuttle did not bring those rattling concerns about its applicability up.

Even so, Tumbler still gave a quick shake of his head to his response, before moving to point a finger towards his own visor.

“That and the optics, don’t let anyone you don’t know get near either of those. Both are entry points.”

“The optics? But the needles would shatter them, surely!”

“There’s a reason love, that I only use that way in on the dead.”

And wasn’t that all just something to dwell on.


End file.
